An unbiased NOEMA 2.6 to 4 mm survey of the GG Tau ring: First detection of CCS in a protoplanetary disk

Context. Molecular line surveys are among the main tools to probe structure and physical conditions in protoplanetary disks (PPDs), birthplace of planets. The large radial vertical temperature as well density gradients these PPDs lead a complex chemical composition, making chemistry an important step understand variety planetary systems. Aims. We aimed study content disk surrounding GG Tau A, well-known triple T Tauri system. Methods. used NOEMA with new correlator PolyFix observe rotational lines at ∼2.6 4 mm from few dozen molecules. analysed data radiative transfer code derive molecular densities abundance relative 13 CO, which we compare those TMC1 cloud LkCa 15 disk. Results. report first detection CCS PPDs. also marginally detect OCS find 16 other molecules outer Ten them had been found previously, while seven others ( CN, N 2 H + , HNC, DNC, HC 3 N, CCS, C 34 S) detections this Conclusions. analysis confirms that sulphur is not yet properly understood. D/H ratio, derived DCO /HCO DCN/HCN, DNC/HNC ratios, points towards low chemistry. rare species good laboratory chemistry, thanks its size mass.